Image reading apparatus

ABSTRACT

A document reading apparatus includes a feeding roller for feeding a document, a reading unit for reading images of the document fed by the feeding roller and a substantially U-shaped document transfer path for guiding the document fed the feeding roller. The substantially U-shaped document transfer path is constituted by an internal guide and an external guide. The external guide is separated from the internal guide by rotating the external guide. The internal guide is rotatably disposed and supports the reading means. A reading transfer path in which the reading unit is arranged is opened by rotating the internal guide.

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] The present invention relates to an image reading apparatus.

[0003] 2. Description of the Related Art

[0004] As a unit for reading image information on each side of documentspiled on a document tray during conveying process, a so-called ADF (AutoDocument Feeder) has been known for a long time.

[0005] The ADF is classified by the presence of a document reversingunit and a reading out unit as follows.

[0006] (1) Single-sided document ADF (FIG. 5):

[0007] Documents piled on a document tray 1001 are separated one by one,and conveyed onto a platen 1002, so as to read out images in an imagereading unit 1003, and then, are discharged.

[0008] (2) Double-sided document ADF with a turning-over unit (FIG. 6):

[0009] After the first side is read out by the image reading section1003, the document is turned over by a turning-over unit 1005 so as toconvey the turned-over document on the platen 1002 again so as to readout the rear side as the second side.

[0010] (3) Double-sided document ADF with reading units (FIG. 7):

[0011] In an ADF device, a first reading unit 1006 and a second readingunit 1007 are arranged along a document transfer path so as tosimultaneously read both sides during conveying the document.

[0012] Among above three ADFs, although (1) is most inexpensive, itcannot read out double-sided documents automatically so as to have afault of low productivity.

[0013] In the double-sided document ADF with the turning over unit of(2), since after separating one document from the documents on thedocument tray so as to convey it to a predetermined reading position forreading out one side, it is turned over and conveyed to thepredetermined reading position again for reading out the other side andbeing discharged thereafter. Because of this double-sided readingprocedure, there is a problem of low reading efficiency.

[0014] Also, since the transfer path becomes complicated, a problem mayarise in that a document may be damaged during transferring.

[0015] Then, as for the double-sided document ADF with the reading units(3), since both sides are simultaneously read during the conveying ofthe document using two optical systems, although it is expensive, thisis very excellent in productivity in comparison with other ADFs.

[0016] When the three ADFs are compared, the double-sided document ADFwith the reading units of (3) is most excellent in productivity, so thatthis type of ADF may make progress quickly from now on.

[0017] In common double-sided document reading ADFs, as disclosed inJapanese Patent Publication No. 2928449, a first reading unit forreading one side and a second reading unit for reading the other sideare arranged above and below with a document conveying path therebetweenso that a document is read out through openings of guide plates.

[0018] However, this type of ADF with the reading units employs aso-called reduction optical system for the other side reading unit,which includes a light source, a plurality of turnover mirrors, a lens,and a CCD, so that the reading unit itself is large in size.

[0019] Therefore, the transfer path is substantially straight from paperfeeding to discharge, so that the discharge tray is forced to protrudeoutside the ADF.

[0020] Then, Japanese Patent Laid-Open No. 11-69086 and Japanese PatentLaid-Open No. 11-327221 propose techniques for solving such problems.

[0021] The double-sided document reading apparatus described in thepublication reduces the entire apparatus in size using a contact-typesensor instead of a reduction optical system so as to form a U-turnpath.

[0022] In order to treat paper jamming not only for the ADF but for apaper conveying device, it is desirable to have an open/close mechanismfor a transfer path.

[0023] Since the U-turn path becomes complicated more than a straightpath, the open/close mechanism is especially indispensable.

[0024] Also, when dust exists in a document reading portion of theother-side reading unit, image defects such as black streaks and whitestreaks may be produced. Therefore, the maintenance for the documentreading portion of the other-side reading unit must be easily performed,so that a mechanism for opening the document reading portion isindispensable.

[0025] In the double-sided reading apparatus disclosed in JapanesePatent Laid-Open No. 11-69086 or No. 11-327221, the contact-type sensorfor reading the other side is arranged inside a transfer guide of theU-turn path.

[0026] Also, the double-sided reading apparatus disclosed in JapanesePatent Laid-Open No. 11-327221 has a two-stepped open/close hingelocated at the end of the apparatus so as to achieve to treat thejamming inside the U-turn path; however its structure is verycomplicated and the mechanism itself is expensive.

[0027] Although the Japanese Patent Laid-Open No. 11-69086 does notspecify an open/close mechanism of the transfer path in the vicinity ofthe contact-type sensor, the contact-type sensor is arranged in thelower portion of the feeding tray so as to have a considerablycomplicated arrangement. Therefore, when the open/close mechanism is tobe adopted, the considerably complicated mechanism cannot be avoided.

SUMMARY OF THE INVENTION

[0028] The present invention has been made in view of the problemsdescribed above, and it is an object of the present invention to providea reading apparatus excellent in jamming-treatment performance andmaintenance by simplifying a transfer path of the reading apparatus andits open/close mechanism.

[0029] In order to achieve the above object, an image reading apparatusaccording to the present invention includes a feeding means for feedinga document; a reading means for reading images on the document fed bythe feeding means; a substantially U-shaped document transfer path forguiding documents fed by the feeding means, which is constituted by aninternal guide and an external guide; and a reading transfer path, inwhich the reading means is arranged, and which is a part of the documenttransfer path; wherein the external guide is rotatably disposed and isseparated from the internal guide by rotating the external guide,wherein the internal guide is rotatably disposed and supports thereading means, and the reading transfer path is opened by rotating theinternal guide.

[0030] Also, an image reading apparatus according to the presentinvention includes a feeding means for feeding documents; a firstreading means for reading images on a first side of the document fed bythe feeding means, the first reading unit being able to read images ofthe document placed on a platen; a second reading means for readingimages on a second side of the document fed by the feeding means; asubstantially U-shaped document transfer path for guiding documents fedby the feeding means, which is constituted by an internal guide and anexternal guide; and a reading transfer path, in which the second readingmeans is arranged, and which is a part of the document transfer path;wherein the external guide is rotatably disposed and is separated fromthe internal guide by rotating the external guide, wherein the internalguide is rotatably disposed and supports the second reading means, andthe reading transfer path is opened by rotating the internal guide.

[0031] Further objects, features and advantages of the present inventionwill become apparent from the following description of the preferredembodiments with reference to the attached drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

[0032]FIG. 1 is a sectional view of a double-sided document ADFaccording to an embodiment of the present invention.

[0033]FIG. 2 is a drawing showing an opened state of a transfer path ofthe double-sided document ADF according to the embodiment of the presentinvention.

[0034]FIG. 3 is a perspective view of a transfer guide unit according tothe embodiment of the present invention.

[0035]FIG. 4 is a perspective view of the vicinity of a second platenroller according to the embodiment of the present invention.

[0036]FIG. 5 is a sectional view of a conventional single-sided documentADF.

[0037]FIG. 6 is a sectional view of a conventional double-sided documentADF with a turnover unit.

[0038]FIG. 7 is a sectional view of a conventional double-sided documentADF with a reading unit.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0039] The present invention will be described below by exemplifyingembodiments with reference to the drawings.

[0040]FIG. 1 is an entire drawing of an ADF according to a firstembodiment.

[0041] The ADF according to the embodiment includes a scanner section100, a document reading/conveying section 200 mounted on the scannersection 100, a document tray 300 for supporting a document S to be fedto the document reading/conveying section by pressing a book documentonto a platen glass plate, and a discharge tray 400 for supporting thedocument S from which images have been read.

[0042] Next, the scanner section 100 and the document reading/conveyingsection 200 will be described in more detail.

[0043] The scanner section 100 includes a first reading unit 1 disposedwithin a casing, a platen glass plate 2 for a book document disposed onthe casing, and a platen glass plate 3 for a sheet document.

[0044] The first reading unit 1 provided in the scanner section 100 isfixed at the position shown in FIG. 1 when reading the document conveyedby the document reading/conveying section 200.

[0045] When a book document or a document incapable of using an ADF isread, by integrally rotating the document reading/conveying section 200,the document tray 300, and the discharge tray 400 about a hinge (notshown) so as to open the platen glass plate 2 for a book document, thedocument is placed and read by reciprocating the first reading unit 1between broken-line positions shown in FIG. 1 corresponding to adocument size by a drive unit (not shown).

[0046] The first reading unit 1 is composed of a lamp 4, a plurality ofturnover mirrors 5, 6, 7, 8, and 9, a lens 10, and a photoelectrictransducer 11 such as a CCD.

[0047] The document reading/conveying section 200 is composed of afeeding roller 12 as a feeding means, a separation transfer roller 13for preventing the double feeding of the fed document, separation pads14 and 15, a transfer guide unit 16, an upper transfer guide 17 servingalso as an external cover, a transfer roller pair 18 and 19, a lowerframe 21 having a transfer guide, a first platen roller 22 with a whitesurface, a second platen roller 23, a discharge roller pair 24, and asecond reading unit 25 as a reading unit for reading the other side. Theseparation transfer roller 13 can abut the separation pad 15, and theseparation transfer roller 13 and the separation pads 14 and 15constitute a separation unit.

[0048] Although description is omitted, the image data read by thesecond reading unit 25 is controlled and processed in a series ofreading and imaging operations by a control substrate (not shown).

[0049] Then, details will be further described by adding operationsthereto.

[0050] From the documents placed on the document tray 300, the feedingroller 12 feeds the document on top of the document tray 300 in a statethat its front bottom surface is supported by a transfer rib 51 (feedingguide) formed on the upper surface of a case 58 of the transfer guideunit 16 so as to be conveyed.

[0051] The feeding roller 12 is normally retracted upward at a positionindicated a broken line in the drawing, which is a home position, so asnot prevent a document from being set.

[0052] Upon starting of feeding operation, the feeding roller 12 is todescend to a position indicated by a solid line of the drawing so as toabut the top surface of the document S.

[0053] Even if several numbers of documents are simultaneously fed, theyare separated into one sheet by the separation transfer roller 13 andthe separation pads 14 and 15 made of a rubber material and is conveyed.

[0054] The separated document S is conveyed at a predetermined speedalong the transfer rib 51 and a transfer rib 52 formed inside theexternal cover, and then is conveyed toward the platen glass plate 3 fora sheet document by the following transfer roller pair 18 and 19 afterbeing conveyed toward a transfer surface 53 of the lower frame 21 and aguide plate 54.

[0055] The surface of the first platen roller 22 is white, and it isrotatable at a speed similar to a predetermined reading speed.

[0056] Then, the document S passes through between the platen glassplate 3 for a sheet document and the first platen roller 22 above thefirst reading unit 1 at the predetermined reading speed, so that theimage information reading of a first side (the bottom surface in thedrawing) is started.

[0057] Next, after the edge of the document S is drug up on a jump table55, the document S is conveyed toward between a transfer surface 56 ofthe lower frame 21 and a guide plate 57, and then conveyed toward thesecond reading unit 25 by the transfer roller pair 19.

[0058] The transfer guide unit 16 includes the case 58, the separationpads 14 and 15 attached to the case 58, and the second reading unit 25.The second reading unit 25 is composed of a contact-type sensor, and asshown in FIG. 3, is fixed to a recess 70 of the case 58 integrally withthe transfer guide unit 16 so that the reading surface of the secondreading unit 25 directs downward by a predetermined fixing unit.

[0059] The case 58 is an integral molding, and includes an internalguide 99 forming the inside of a substantially U-shaped documenttransfer path and a feeding guide 98 for holding an edge of documentsplaced on the document tray 300. The feeding guide 98 is provided withthe transfer rib 51 formed thereon.

[0060] Upstream a recess 71 of the case 58, a plurality of readingtransfer ribs 59 (reading guides) are formed in the case 58 for guidingthe document S to the second reading unit 25. The document S is conveyedto a reading position of the second reading unit 25 while being conveyedto the reading transfer ribs 59 and the transfer surface 56 of the lowerframe 21 passing through the reading transfer ribs 59, a reading surface25 a of the second reading unit 25, the transfer surface 56 of the lowerframe 21, and a reading/transfer path R.

[0061] The surface of the second platen roller 23 is white, and it isrotatable at a speed similar to a predetermined reading speed in thesame way as in the first platen roller 22.

[0062] Bearings 62 (one shown only in the drawing) of the second platenroller 23 provided at both ends, as shown in FIG. 4, are upward urged bysprings 63 (one shown only in the drawing), and the second platen roller23 has rollers 64 (one shown only in the drawing) coaxially arranged atboth ends of the roller section with a diameter slightly larger thanthat of the roller section.

[0063] By urging the rollers 64 on the surface of the second readingunit 25 with forces of the springs 63, the second reading unit 25 andthe surface of the second platen roller 23 are arranged so as to have aslight clearance to the extent that one sheet of the document S passestherethrough.

[0064] Upon passing through of the document S between the second readingunit 25 and the second platen roller 23 at the predetermined readingspeed, the reading out of image information of a second side (uppersurface in the drawing) is started.

[0065] The document S after finishing the reading passes between aplurality of transfer ribs 60 disposed downstream the second readingunit 25 of the transfer guide unit 16 and the transfer surface 56 of thelower frame 21 and is conveyed outside the apparatus toward thedischarge tray 400 by the discharge roller pair 24. Upon finishingconveying the first sheet, the document is sequentially conveyed fromthe documents S placed on the document tray 300, and after the lastdocument s is discharged, the apparatus is stopped to operate.

[0066] The feeding and the conveying are driven by a motor (not shown).

[0067] In such a manner, by the first reading unit 1 of the scannersection 100 and the second reading unit 25 mounted on the documentreading/conveying section 200, both sides of the double-sided document Scan be read during one-time transfer.

[0068] Next, the opening of the apparatus for jamming treatment ormaintenance will be described with reference to FIG. 2.

[0069] The external cover 17 is constructed rotatably about a coverfulcrum 61 counterclockwise in the drawing.

[0070] At this time, the feeding roller 12 and the separation transferroller 13 are also rotated together with the external cover 17.

[0071] By rotating the external cover 17, the external guide 52 formedon the external cover 17 is separated from the internal guide 99 of thecase 58. By this operation, a curved document transfer path C defined bythe external guide 52 and the internal guide 99 of the case 58 isopened. Also, a feeding transfer path F defined by the external guide 52of the external cover 17 and the feeding guide 98 formed on the uppersurface of the case 58 is simultaneously opened. Accordingly, jammingcan be easily treated.

[0072] Then, the jamming treatment or maintenance for a portion belowthe transfer guide unit 16 will be described. The transfer guide unit 16is rotatable about the shaft of the discharge roller 24 so that theinternal guide 99 formed on the case 58 moves upward.

[0073] The recesses 71 formed at both ends of the case 58 of thetransfer guide unit 16 is normally in a state abutting the transfersurface 56; during the jamming treatment and maintenance, this transferguide unit 16 itself is rotated clockwise in the drawing.

[0074] By this operation, a reading transfer path R defined by thereading transfer ribs 59 formed under the transfer guide unit 16 and thetransfer surface 56 of the lower frame is opened so that the jammingtreatment and maintenance are easily conducted. In addition, thesubstantially U-shaped document transfer path according to the presentinvention is defined by the curved document transfer path C and thereading transfer path R.

[0075] According to the embodiment, the reading unit is arrangedintegrally with the transfer guide unit, and the guide surfaces areformed on both sides that are the reading surface of the transfer guideunit (adjacent to the reading transfer path R) and the opposite side(adjacent to the feeding transfer path F) disposed substantially inparallel therewith, while the transfer guide unit is movable, so thatthe opening operation required for the jamming treatment and maintenancecan be achieved with a simple mechanism.

[0076] Since the case of the transfer guide unit is made of a resin andthe transfer rib is integrally formed, a very inexpensive openingoperation mechanism is achieved.

[0077] While the present invention has been described with reference towhat are presently considered to be the preferred embodiments, it is tobe understood that the invention is not limited to the disclosedembodiments. On the contrary, the invention is intended to cover variousmodifications and equivalent arrangements included within the spirit andscope of the appended claims. The scope of the following claims is to beaccorded the broadest interpretation so as to encompass all suchmodifications and equivalent structures and functions.

What is claimed is:
 1. An image reading apparatus comprising: a feedingmeans for feeding a document; a reading means for reading images on thedocument fed by the feeding means; a substantially U-shaped documenttransfer path for guiding documents fed by the feeding means, which isconstituted by an internal guide and an external guide; and a readingtransfer path, in which the reading mean is arranged, and which is apart of the document transfer path; wherein the external guide isrotatably disposed and is separated from the internal guide by rotatingthe external guide, wherein the internal guide is rotatably disposed andsupports the reading means, and the reading transfer path is opened byrotating the internal guide.
 2. An apparatus according to claim 1,wherein the reading means comprises a contact-type sensor.
 3. Anapparatus according to claim 1, wherein the internal guide is made of aresin and has a plurality ribs.
 4. An apparatus according to claim 1,wherein the external guide is rotatable about the apparatus body in adirection opposite to the rotational direction of the internal guide. 5.An apparatus according to claim 4, wherein after the external guide isrotated, the reading transfer path of the document transfer path isopened by rotating the internal guide.
 6. An apparatus according toclaim 1, wherein the internal guide comprises: a reading guideconstituting the reading transfer path; and a feeding guide constitutinga feeding path, in which the feeding means arranged, and arrangedsubstantially in parallel with the reading transfer path.
 7. Anapparatus according to claim 6, further comprising a cover having theexternal guide; and a separating roller and separating pad abutting theseparating roller for separating a document fed by the feeding means oneat a time, wherein the cover is rotatable about the apparatus body in adirection opposite to the rotational direction of the internal guide,and the external guide is separated from the internal guide by rotatingthe cover, and wherein the feeding means and the separating roller aredisposed on the cover; and the separating pad is disposed on theinternal guide.
 8. An apparatus according to claim 1, wherein therotation center of the internal guide is provided upstream the readingmeans in a direction of feeding a document by the feeding means.
 9. Animage reading apparatus comprising: a feeding means for feedingdocuments; a first reading means for reading images on a first side ofthe document fed by the feeding means, the first reading means beingable to read images of the document placed on a platen; a second readingmeans for reading images on a second side of the document fed by thefeeding means; a substantially U-shaped document transfer path forguiding documents fed by the feeding means, which is constituted by aninternal guide and an external guide; and a reading transfer path, inwhich the second reading means is arranged, and which is a part of thedocument transfer path, wherein the external guide is rotatably disposedand is separated from the internal guide by rotating the external guide,and wherein the internal guide is rotatably disposed and supports thesecond reading means, and the reading transfer path is opened byrotating the internal guide.
 10. An apparatus according to claim 9,wherein the external guide is rotatable about the apparatus body in adirection opposite to the rotational direction of the internal guide.11. An apparatus according to claim 9, wherein a reading position by thesecond reading means is located downstream a reading position by thefirst reading means on the document transfer path.
 12. An image readingapparatus comprising: a feeding roller which feeds a document; a readingunit for reading images on the document fed by the feeding roller; adischarge roller which discharges the document read by the reading unit;a substantially U-shaped document transfer path disposed between thefeeding roller and the discharge roller, which is constituted by aninternal guide and an external guide; and reading transfer path, inwhich the reading unit is arranged, and is a part of the documenttransfer path, wherein the external guide is rotatably disposed and isseparated from the internal guide by rotating the external guide, andwherein the internal guide is rotatably disposed and supports thereading unit, and the reading transfer path is opened by rotating theinternal guide.